Architect and city planner. Isaacs studied architecture at the University of Minnesota and Harvard's Graduate School of Design. He went on to receive a degree in planning from the University of Chicago. Isaacs career was devoted to planning and housing projects in places as far flung as Chicago and the Virgin Islands. In 1951, he became the Charles Dyer Norton Professor of Regional Planning at Harvard. He served as chair of the Department of City and Regional Planning from 1953-1964. In 1983, Isaacs published a German-language biography of his former teacher, Walter Gropius. Isaacs corresponded with Breuer, who helped him acquire a sketch by Fernand Léger.